This past summer, FiveThirtyEight took on the somewhat ridiculous task of searching for America’s Best Burrito. Knowing this effort would be Herculean, we enlisted the help of Yelp and a panel of food experts to guide us. Nate Silver created a statistic — value over replacement burrito, or VORB — to rate and rank each of 67,391 burrito-selling establishments (BSEs) in the United States listed on Yelp. He used a variety of metrics, including how many reviews a restaurant had, how many of those reviews mentioned burritos, and the average star rating. We then took that list and huddled with the food experts, our Burrito Selection Committee, to choose just 64 BSEs, which were placed into an NCAA-style bracket.

My job as burrito correspondent was to find the best burrito in the United States. So, armed with the list of 64 BSEs, I hit the burrito trail. I spent four months driving more than 25,000 miles back and forth across the country, taking thousands of pictures and writing more than 47,000 words about burritos. Every few days, we published a review of four restaurants, and I named my favorite based on a scoring rubric I created to evaluate the burritos. The best of the four then advanced to the next round in the tournament. In three rounds, we narrowed the Burrito Bracket from from 64 BSEs to 16 and then ultimately four finalists. Earlier this month, we crowned the winner: La Taqueria in San Francisco.

While the goal really was to find the best burrito, we also wondered what the average Yelp user could learn from using the site. Yelp is great for finding information about restaurants — addresses, phone numbers and hours — but what could it tell us about food? In Nate’s article explaining the methodology behind VORB, he also explained our thinking going into the project:

The question of how consumers might use crowdsourced data to make better decisions is an important one. Billions of dollars turn upon customer reviews at sites like Yelp, Amazon, Netflix and HealthGrades. How should you evaluate crowdsourced reviews as compared to the recommendations from a professional critic, or a trusted friend? Are there identifiable biases in the review sites and ways to correct for them? When using sites like Yelp, should you pay more attention to the number of reviews, or to the average rating?

We had a couple of ways to test the accuracy of the Yelp data. First, did the Yelp ratings conform to our experts’ opinions? In most cases they did; the Burrito Selection Committee members found many of their favorite burritos at the top of the VORB list in each region. Second, did I like the highly rated burritos when I tasted them? Again, yes; with a few exceptions, every burrito in the bracket was one I would go back to eat, and the exceptions all came from our desire to include geographic and stylistic diversity.

The next question was how the VORB scores compared to my Burrito Bracket scores. Let’s assume for a minute that VORB is a good measure of the popularity of a restaurant on Yelp. If we had simply placed the 64 restaurants with the highest VORB scores in our bracket and then tasted all 64 burritos, we would have learned whether the crowdsourced data was a good indication of the quality of food at those 64 restaurants.

However, we assumed that the crowdsourced data wasn’t completely reliable — not every great burrito would do well on Yelp, and some restaurants with mediocre food are very popular. That’s why we enlisted the panel of experts to choose which restaurants would make the bracket. Our experts selected several restaurants because they had personal experience or information suggesting the food there was good, in spite of low VORB scores. With the inclusion of these restaurants, the only way there could be a correlation between VORB scores and my scores was if the food experts were all wrong.

Indeed, I found no correlation between my scores and VORB scores, or the individual measures used to create VORB: number of reviews, average stars in all reviews, average stars in reviews that mentioned burritos, and number of reviews mentioning burritos. This implies that crowdsourced data alone may not be sufficient for finding great food, and that expert knowledge continues to play an important role.

I decided to take a look back at all of the BSEs in the bracket to see whether there was any relationship between higher scores from me and how a restaurant made it into the bracket (high VORB score or expert recommendation). I loosely organized them into the categories of Yelp, Human or Both, the last for restaurants with the clear support of both sources. I found that 19 restaurants in the bracket made it in on the recommendation of our panel, despite low VORB scores, while 16 were included because of high VORB scores, even though the experts either had no knowledge of them or didn’t recommend them.

So are restaurant reviews on Yelp really about food? When I spoke to a group of Yelp employees this summer, they explained that a review on the site is meant to reflect the overall dining experience. Translation: Yelp reviews aren’t just about the food. Of course, anyone who has used Yelp (either as a reference, or to write reviews) knows that. But I did want to know to what degree the reviews and VORB scores were a reflection of the quality of a restaurant’s food.

I took a deeper dive into the Yelp pages of some of the places where the quality of the food and the VORB scores didn’t match up, either because the food was much better than VORB would suggest, or because the burrito I ate there was mediocre despite a high score. It’s hard to quantify the findings, but here are some trends I found after months spent combing through the reviews:

Yelp usage varies dramatically by region and city, but it also varies by neighborhood. When calculating VORB, Nate took into account how popular Yelp is in each city. I went to several restaurants in neighborhoods with less traffic from Yelp users. Tortilleria y Taqueria Ramirez, with a VORB of 0.7, is a good example. It’s in Lexington, Kentucky, where residents certainly don’t use Yelp to the same degree as those in San Francisco, but the site has a reasonable presence. Ramirez, however, is in a predominantly Hispanic neighborhood on the northwest edge of the city, an area of town that many Lexington residents often don’t travel to.

The caloric-quantity-to-dollar ratio is highly important to Yelpers, at least when it comes to burritos. This is not a value I generally share (among other reasons, I’m a health care journalist who has spent many years reporting on the obesity epidemic), and for the purposes of the Burrito Bracket, we were not taking price into account. Little Donkey had a tiny VORB (partly because only a small fraction of reviews of the restaurant mentioned its burritos) but a large percentage of the negative reviews complained that the portions were too small. Likewise, the Chuck Norris burrito from Mi Casita in Longview, Texas, got rave reviews because of its obscene size. But its girth made for a burrito that wasn’t particularly good, despite very tasty individual ingredients.

Yelp is all about expectations. Unfulfilled expectations lead to bad reviews. But reading reviews on Yelp before a visit can help manage expectations. Take, for example, this one-star review of Little Donkey, which specializes in Mexican cuisine using Southern smoking techniques: “The restaurant seems to have an identity crisis, Americana meets BBQ meets tex-mex perhaps. Everything we tried had an overbearing and unwanted smoky flavor.”Measuring expectations is a difficult task, and not one the Burrito Bracket could complete, but doing so would likely yield interesting information about Yelp reviews.

Yelp reviews often tell you more about the reviewer than about the restaurant, such as her pet peeves and what kind of day she was having when she wrote a review. This is related to expectations, but it takes a certain amount of Yelp literacy to know how to filter those personalized critiques. Bell Street Burritos in Atlanta served delicious burritos, though the restaurant had a low VORB and a lot of negative reviews. A look at reviews with high and low ratings suggested most were drawn from very personalized opinions. On the positive end, we had memory: “heard it was the 2nd coming of Tortilla’s, an amazing original burrito joint that sadly closed a long time ago. I took that first bite and I felt a rush of nostalgia, joy and completeness.” On the negative end: “I am mexican and this did not meet my standards,” and “You have a tortilla right, so it SHOULD be filled with tasty things and flavor, not plain white rice!” I’ve never been to Tortilla’s, so nostalgia didn’t season this burrito for me, but I also didn’t expect traditional Mexican food in a restaurant in Atlanta owned by a Georgia native.

Poor service trumps great food. Good service and atmosphere combined with mediocre food tends to score three to four stars on Yelp, while good food and bad service often ends in a one-star rating. If the service is consistently poor, this may be useful. However, if all the reviews for the place with the best carnitas in town are one star because the man behind the counter is rude, this may not be helpful when what you care about is getting a good dose of fried pork.

There is a lot of noise. If I landed in San Francisco with no knowledge of the city’s food offerings and looked up “burrito” on Yelp, it would be easy to identify 10 popular burrito-selling establishments, but it would be hard to know which were really good, or most suited to my taste. Many rabid fans of Taqueria Cancún and La Taqueria dislike the other place, while I contend that both are great. It would be hard to know the differences between the two based on Yelp alone (other than perhaps gathering that Cancún uses rice and La Taqueria does not).

The abundance of online sites such as Yelp, Menupages and UrbanSpoon have made it difficult to search for professional reviews, which are still incredibly useful. For starters, food critics generally go back to a location several times to evaluate consistency. When the Burrito Bracket began, a Google search for La Pasadita in Chicago didn’t turn up any reviews published by professional reviewers. Had it, I might have been prepared for the restaurant’s inconsistency across visits.

Crowdsourced reviews can reveal house specialties, or foods to avoid. They can also lead to items not found on the menu, as one review did for me in Norman, Oklahoma. There, I found that one of the most popular burritos at Pepe Delgado’s, “The Thing,” wasn’t on the menu.

Footnotes

Twenty-seven BSEs had both support from the panel and a high VORB score. Of those, 56 percent received a score of 80 or higher from me.

Anna Maria Barry-Jester reports on public health, food and culture for FiveThirtyEight. @annabarryjester